Ashphalt compositions containing polyamide

ABSTRACT

A composition comprised of from about 70 to about 95 percent by weight asphalt and from about 30 to about 5 percent by weight of N,N&#39;&#39;-distearyl-ethylenediamide, preferably from about 85 to about 92 percent, and from about 15 to about 8 percent, respectively, has desirable properties with regard to softening point, viscosity, and penetration.

United States Patent Moran 1151 3,660,126 1 May 2,1972

[54] ASHPHALT COMPOSITIONS CONTAINING POLYAMIDE [72] Inventor: CharlesE. Moran, Pinole, Calif.

[73] Assignee: Chevron Research Company, San Francisco, Calif.

[22] Filed: Jan. 16,1970

[21] Appl.No.: 3,530

[52] US. Cl ..l06/279, 117/123, 208/22,

[51] Int. Cl. .....CO8h 13/00, CO8h 17/22, CO8j 1/46 [58] Field ofSearch 106/142, 273-284; 117/1355, 140, 123, 168,260/4045; 94/20, 23;

[56] References Cited UNITED STATES PATENTS 2,425,392 8/1947 Robinson eta1 ..260/404.5

Primary Examiner-Joan B. Evans Attorney-A. L. Snow, F. E. Johnston, G.F. Magdeburger and B. l. Rowland ABSTRACT A composition comprised offrom about 70 to about 95 percent by weight asphalt and from about 30 toabout 5 percent by weight of N,N' distearyl-ethylenediamide, preferablyfrom about 85 to about 92 percent, and from about 15 to about 8 percent,respectively, has desirable properties with regard to softening point,viscosity, and penetration.

4 Claims, No Drawings BACKGROUND OF THE INVENTION 1. Field oftheInvention Asphalt-based compositions are widely used to providewaterproof coatings on a wide variety of materials; Among thesematerials are roofing felts, concrete and masonry structures, insulatingsheets, and casings of various types.

When coating the internal surface of cylindrical casings and othersimilar structure, certain problems arise. When the casing is ofrelatively small diameter, attempts to spread the asphalt compositionover the internal surface by means of a brush or roller are ineffective.If the composition is sprayed on the internal surface, the asphalt tendsto run off, thereby givmg uneven coating.

Since one of the fastest and most economical manners in whichtheinternal surfaceof casings can be coated is to inject a spray of theasphalt-based material into the interior of the casing while spinningthe casing or conversely, the sprayer head, a composition which will setup quickly to avoid running is highly desirable. Unfortunately, toenable asphalts to be sprayed, high temperatures are required to reducethe viscosity. This has the effect of rapidly heating the casing,particularly where it is metallic, so that the asphalt does not coolfast enough to prevent its running off. One method of solving thisproblem is to cool the outside surface of the casing by use of a coolingmedium such as a water spray. However, this method requires the setup ofadditional equipment, subsequent drying of the casing, and is notreadily adaptable to the in-the-field use. Further, where the casing tobe coated is cement or other similar material with a low thermalconductivity, the reduction in temperature of the outer surface does notreduce the temperature on the internal surface effectively.

Therefore, the development of an asphalt-based material which meetscertain minimum standards with regard to softening point, viscosity, andpenetration to prevent this running off and to provide useful coatingswould be highly desirable. These minimum specifications are goodfluidity of the coating composition at around 300 F., a fast setup,i.e., the coating becomes hard and will not run at about 150 to 200 F.,and the coating does not become excessively hard at ambient and lowertemperatures. r

Further evidence of the desirability of a product with these features isshown by the requirements of Military Specification MlL-C3301A for bombcavity lining asphalt. The specification calls for a minimum penetrationat 77 F. of 25, a softening point, R and B, of 235 F. minimum, and aviscosity SUMMARY OF THE INVENTION A composition comprised of a majoramount of an asphalt and a minor amount ofN,N-distearyl-ethy1enediamide, has desirable properties with regard tosoftening point, viscosity, and penetration when used as a coating inapplications where a fast setup is desired.

DETAILED DESCRIPTION OF THE INVENTION The Composition The composition ofthis invention comprises from about 70 to about 95 percent (preferablyfrom about 85 to about 92 percent) by weight of an asphalt having apenetration of from 7 to about and a softening point of from about 200to about 300 F., and from about 30 to about 5 percent (preferably fromabout 15 to about 8) by weight of N5- distearyl-ethylenediamide.

The Asphalt The asphalts of this invention may be selected from a rangeof asphaltic materials. The only criteria are that the penetration at 77F. must be in the range from about 7 to about 50(ASTM D-5-65), and thesoftening point must be in the range of from about 200 to about 300 F.Airblown asphalts meet these criteria and are particularly useful. Thelow temperature rheological properties of the asphalt are affectedrelatively little by the additive. The desired low temperaturerheological properties are, therefore, obtained by selecting the asphalthaving these desired properties as the base material.

The preferred asphalt is Petrolastic Culvert Asphalt T1 13 (a product ofChevron Asphalt Company). This asphalt has a penetration at 77 F.(ASTM-D-5-65) of 43 a viscosity at 300 F. of 10,700 cp., and a softeningpoint of 222 F.

Another specific example of a satisfactory asphalt is PetrolasticAsphalt No. 3 (a product of Chevron Asphalt Company) having apenetration in the range of ISO-35 at 77 F. (ASTM-D-5-65) and asoftening point in the range of 200-210 F.

The Diamide The diamide used in this invention is N,N-distearylethylenediamide of the formula The diamide is a hard, light-colored,waxymaterial having a melting point of about 280 F., and a flash pointof 530 F.

I C.O.C. It is soluble in hot naphtha, hot toluene, and most hot at 300F. of 700 cp. maximum,(Brookfield L.V.F., No. 2 spindle at 12 rpm.). Thematerial must not sag at 228 F. and no disintegration, browning, ordulling after 6 hours exposure to hydrochloric acid is permitted After18 hours exposure to water, the material may be no more than slightlydull. The material must not crack upon bending and must also have aminimum flash point, COC, of 500 F. It is believed that unmodifiedasphalt compositions per se do not fulfill all of these requirements.

2. Description of the Prior Art U.S. Pat. No. 2,891,873 to Falkenburg etal. discloses and claims a bituminous composition comprised of asphaltand an additive in an amount offrom 0.1 to 3 percent by weight oftheasphalt. The additives serve as anti-stripping agents in asphalticpaving compositions for improving the adherence of the asphalt to wet ordry aggregates Among the additives taught by the reference is thestearic acid compound of diethylene triamine having the formula:

U.S. Pat. No. 3,026,266 to Mertens et a1. discloses asphaltic emulsionshaving incorporated therein from about 0.1 to about 1.5 percent of apolyamide product of condensation of polycarboxylic acid and acyclicpolyalkylene polyamines.

organic solvents. It is insoluble in water and in alcohols.

Preparation of the Composition The composition is prepared by combiningthe ingredients with constant agitation at 300-325 F. until ahomogeneous mixture is obtained. Conventional mixing apparatus can beused, such as a heated tank with an impeller or with a sparge throughwhich is bubbled steam or nitrogen to create agitation. The diamide canbe added in the form of flakes to the hot asphalt or, alternatively, thediamide can also be heated to 300-325 F. and the two constituentscombined with stirring. The latter method is preferred to avoid lumps ornonhomogeneous mixtures and to reduce the mixing time.

EXAMPLES The compositions set forth in Table 1 were prepared by mixingthe quantities of asphalt and diamide set forth in the table. Theasphaltin each case, Petrolastic Culvert Paving Asphalt T-l 13 (as describedearlier), was heated to 300 F. in an open vessel and the diamine in eachcase, Carlisle 780, N,N' distearyl-ethylenediamide (as describedearlier) was added in the form offlakes with constant mixing. Mixing wascontinued for ten minutes to insure homogeneity. The mixture was thenallowed to cool and the viscosity, penetration, and softening point weresubsequently measured with the results shown in Table I.

TABLE I Penetra- Viscosity, Percent .tion, 300 F Softening Percentasphalt diamide 77 F. .centipoise point The compositionsall satisfiedthe specifications set forth in limited only as set forth in thefollowing claims.

I claim:

1. A composition comprising from about 70 to about 95 percentby weightasphalt having a penetration of from about 7 to about and a softeningpoint of from about 200 to about 300 F., and from about 30 to about 5percent by weight N ,N -distearyl-ethylenediamide.

2. Claim 1, wherein said asphalt is present in an amount of from about85 to about 92 percent by weight and said diamide is present in anamount of from about 15 to about 8 percent by weight.

3. Claim 2, wherein said asphalt has a softening point of about 222 F.,a penetration at 77 F. of about 43, and a viscosity of 10,700 cp. at 300F.

4. Claim 3, wherein said asphalt is present in an amount of about 90percent by weight and saiddiamide is present in an amount of about 10percent by weight.

l I 1F 1F k

2. Claim 1, wherein said asphalt is present in an amount of from about85 to about 92 percent by weight and said diamide is present in anamount of from about 15 to about 8 percent by weight.
 3. Claim 2,wherein said asphalt has a softening point of about 222* F., apenetration at 77* F. of about 43, and a viscosity of 10,700 cp. at 300*F.
 4. Claim 3, wherein said asphalt is present in an amount of about 90percent by weight and said diamide is present in an amount of about 10percent by weight.